Movement Joints in Floor Tiles and Underfloor Heating

When installing underfloor heating, it pays to do a bit of investigation on how the subfloor is built. If it has a movement joint, also known as an expansion joint, this joint has to be carried through to the tiled surface, or in time there may be a crack in the floor. Added to which, according to the Tile Association guidelines, if the surface of the heated floor is over 3.5×3.5m2 then there needs to be a movement joint added regardless.

When the underfloor heating is laid, the floor needs to be commissioned before tiling. In other words, this means that the temperature needs to be increased incrementally over a couple of days until the maximum temperature is reached. Then turned down until it is cold. This places stress on the floor and any cracks larger than 1mm can then have remedial work carried out on them. This is to avoid cracks in the floor tiles due to future cracking in the subfloor, if commissioning was not done.

With these precautions in place, you have a much higher chance of prolonging the life of the tiled floor.